using Common.AspNetCore.Extensions;
using Common.Frame.Services.Cache.Interfaces;
using Common.NETCore.Utility;
using FASS.Scheduler.Models;
using FASS.Scheduler.Services.CronTasks;
using FASS.Scheduler.Services.EventBus;
using FASS.Scheduler.Services.Extends;
using FASS.Scheduler.Utility;
using FASS.Service.Dtos.Setting;

namespace FASS.Scheduler.Services
{
    public class AppHostService : IHostedService, IAsyncDisposable
    {
        private IHostApplicationLifetime Lifetime { get; }
        private CancellationTokenSource? _startupTokenSource;
        private Task? _startupTask;

        public ILogger<AppHostService> Logger { get; }
        public AppSettings AppSettings { get; }
        public IServiceProvider ServiceProvider { get; }

        public ExtendService ExtendService { get; private set; } = null!;
        public EventBusService EventBusService { get; private set; } = null!;
        public CronTaskService CronTaskService { get; private set; } = null!;

        public AppHostService(
            IHostApplicationLifetime lifetime,
            ILogger<AppHostService> logger,
            AppSettings appSettings,
            IServiceProvider serviceProvider)
        {
            Lifetime = lifetime;
            Logger = logger;
            AppSettings = appSettings;
            ServiceProvider = serviceProvider;

            Lifetime.ApplicationStarted.Register(OnApplicationStarted);
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
            Logger.LogInformation("服务启动中");
            return Task.CompletedTask;
        }

        public async Task StopAsync(CancellationToken cancellationToken)
        {
            Logger.LogInformation("服务停止中");

            var startupTokenSource = Interlocked.Exchange(ref _startupTokenSource, null);
            startupTokenSource?.Cancel();
            var startupTask = Interlocked.Exchange(ref _startupTask, null);
            if (startupTask is not null)
            {
                try
                {
                    await startupTask.WaitAsync(cancellationToken);
                }
                catch (OperationCanceledException) when (startupTokenSource?.IsCancellationRequested == true || cancellationToken.IsCancellationRequested)
                {
                    Logger.LogInformation("服务启动流程已取消");
                }
                catch (Exception ex)
                {
                    Logger.LogError(ex, "服务等待启动流程结束失败");
                }
            }
            startupTokenSource?.Dispose();

            var stopTasks = new List<Task>();
            if (CronTaskService is not null)
            {
                stopTasks.Add(CronTaskService.StopAsync(cancellationToken));
            }
            if (EventBusService is not null)
            {
                stopTasks.Add(EventBusService.StopAsync(cancellationToken));
            }
            if (ExtendService is not null)
            {
                stopTasks.Add(ExtendService.StopAsync(cancellationToken));
            }
            await Task.WhenAll(stopTasks);
        }

        public async ValueTask DisposeAsync()
        {
            Logger.LogInformation("服务释放资源");
        }

        private void OnApplicationStarted()
        {
            if (_startupTask is not null)
            {
                return;
            }

            _startupTokenSource = new CancellationTokenSource();
            _startupTask = RunStartupAsync(_startupTokenSource.Token);
        }

        private async Task RunStartupAsync(CancellationToken cancellationToken)
        {
            try
            {
                Logger.LogInformation("[{Name} V {Version}]", Session.AssemblyName.Name, Session.AssemblyName.Version);

                if (AppSettings.Scheduler.StartupDueTime > 0)
                {
                    Logger.LogInformation("启动延迟：{Delay} 毫秒", AppSettings.Scheduler.StartupDueTime);
                    await Task.Delay(AppSettings.Scheduler.StartupDueTime, cancellationToken);
                }

                Logger.LogInformation("--------初始化--------");

                InitializeCache();
                InitializeService();

                Logger.LogInformation("--------启动--------");

                await Task.WhenAll(
                    ExtendService.StartAsync(cancellationToken),
                    EventBusService.StartAsync(cancellationToken),
                    CronTaskService.StartAsync(cancellationToken));
            }
            catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
            {
                Logger.LogInformation("--------取消--------");
            }
            catch (Exception ex)
            {
                Logger.LogCritical(ex, "错误");
            }
        }

        public void InitializeCache()
        {
            ServiceProvider.GetScopeService<IDataService>().GetConfigToDto<ConfigServiceDto>(CacheKey.Setting.ConfigService);
        }

        public void InitializeService()
        {
            ExtendService = ServiceProvider.GetRequiredService<ExtendService>();
            EventBusService = ServiceProvider.GetRequiredService<EventBusService>();
            CronTaskService = ServiceProvider.GetRequiredService<CronTaskService>();
        }
    }
}